Chair

ABSTRACT

A chair includes a seat assembly, a backrest assembly, a support assembly, and an actuating mechanism. The seat assembly includes a leg unit and a seat plate mounted to the leg unit. The backrest assembly includes a backrest plate and an engaging frame interconnecting pivotally the backrest plate and the seat assembly. The support assembly includes at least one telescopic rod interconnecting the engaging frame and the leg unit. The actuating mechanism includes at least one actuating member corresponding in position to the telescopic rod, and a drawing unit coupled to the actuating member and operable for driving the actuating member to actuate length adjustment of the telescopic rod so as to adjust inclination of the backrest assembly relative to the seat assembly.

BACKGROUND OF THE INVENTION

1. Field of the Invention

The invention relates to a chair, more particularly to a chair that has an inclination-adjustable backrest.

2. Description of the Related Art

Referring to FIGS. 1 and 2, Taiwanese Utility model No. M297674 discloses a chair backrest adjusting device comprising a base plate 11, a backrest plate 13, and an engaging frame 12 having opposite ends that are connected respectively and pivotally to the backrest plate 13 and the base plate 11. The base plate 11 is formed with a through hole 111 disposed adjacent to the backrest plate 13. The engaging frame 12 includes a positioning plate 121 extending through the through hole 111 and formed with a plurality of positioning holes 122. The backrest adjusting device further includes a positioning pin 14 for being inserted into a selected one of the positioning holes 121, a compression spring 15 for biasing the positioning pin 14 toward the positioning plate 121, a handling lever 16 mounted pivotally to the base plate 11, and a torsion spring 17 interconnecting the handling lever 16 and the positioning pin 16.

When the positioning pin. 14 is biased by the compression spring 15 to be inserted into the selected one of the positioning holes 122, the backrest plate 13 is positioned at an inclination relative to the base plate 11. To adjust the inclination of the backrest plate 13 relative to the base 11, the handling lever 16 is pulled for driving the torsion spring 17 to bias the positioning pin 14 away from said one of the positioning holes 121 against a biasing force of the compressions spring 15, thus enabling inclination adjustment of the backrest plate 13. After the backrest plate 13 is moved to another inclination relative to the base plate 11 and the positioning pin 14 is aligned with another one of the positioning holes 122, the handling lever 16 is released and the positioning pin 14 is biased to be inserted into the one of another positioning holes 121 by a restoring force of the compression spring 15 and the torsion spring 17.

However, the configuration of the above-mentioned backrest adjusting device is relatively complicated. Moreover, the backrest plate 13 can not be positioned at any desired angle relative to the base plate 11 due to the limitation of the number of the positioning holes 122, thereby resulting in a relatively low flexibility of the backrest adjusting device during use. Furthermore, since most elements that are included in the backrest adjusting device are rigid elements, the position where the handling lever 16 is mounted to the base plate 11 as well as the direction that the handling lever 16 is allowed to pivot are limited, thus resulting in inconvenience during use.

SUMMARY OF THE INVENTION

Therefore, the object of the present invention is to provide a chair capable of alleviating the above drawbacks of the prior art.

Accordingly, a chair of the present invention includes a seat assembly, a backrest assembly, a support assembly, and an actuating mechanism. The seat assembly includes a leg unit and a seat plate mounted to the leg unit. The backrest assembly includes a backrest plate and an engaging frame that interconnects pivotally the backrest plate and the seat assembly. The support assembly includes at least one telescopic rod that interconnects the engaging frame of the backrest assembly and the leg unit of the seat assembly. The actuating mechanism includes at least one actuating member that corresponds in position to the telescopic rod, and a drawing unit coupled to the actuating member and operable for driving the actuating member to actuate length adjustment of the telescopic rod so as to adjust inclination of the backrest assembly relative to the seat assembly.

BRIEF DESCRIPTION OF THE DRAWINGS

Other features and advantages of the present invention will become apparent in the following detailed description of the preferred embodiment with reference to the accompanying drawings, of which:

FIG. 1 is a top view of a backrest adjusting device disclosed in Taiwanese Utility model No. M297674;

FIG. 2 is a fragmentary partly sectional view of the backrest adjusting device of FIG. 1;

FIG. 3 is a fragmentary bottom perspective view of a first preferred embodiment of a chair according to the present invention;

FIG. 4 is a fragmentary partly sectional view of the first preferred embodiment, illustrating a backrest assembly at an inclination relative to a seat assembly;

FIG. 5 is a fragmentary partly sectional view of a support assembly and an actuating mechanism of the first preferred embodiment, illustrating the support assembly at a state in which the length thereof is unable to be adjusted;

FIG. 6 is a fragmentary schematic top view of the support assembly and the actuating mechanism of the first preferred embodiment;

FIG. 7 is a view similar to FIG. 4, but illustrating the backrest assembly at another inclination relative to the seat assembly;

FIG. 8 is a view similar to FIG. 5, but illustrating the support assembly at a length adjustable state; and

FIG. 9 is a fragmentary schematic top view of a second preferred embodiment of the chair according to the present invention.

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENT

Before the invention is described in greater detail with reference to the accompanying embodiments, it should be noted herein that like elements are denoted by the same reference numerals throughout the disclosure.

As shown in FIGS. 3 to 5, a first preferred embodiment of a chair of the present invention includes a seat assembly 2, a backrest assembly 3, a support assembly 4, and an actuating mechanism 5.

The seat assembly 2 includes a leg unit 21 and a seat plate 22 mounted to the leg unit 21. The leg unit 21 includes a seat-supporting member 211 disposed under and mounted to the seat plate 22, and a leg member 212 disposed under and connected fixedly to the seat-supporting member 211. The seat-supporting member 211 further includes a handle mounting wall 213 at a front part of the seat-supporting member 211, and spaced-apart backrest assembly mounting walls 214 at a rear part of the seat-supporting member 211. The backrest assembly mounting walls 214 extend in a front-rear direction.

The backrest assembly 3 includes a backrest plate and an engaging frame 32 that interconnects pivotally the backrest plate 31 and the seat assembly 2. The backrest plate 31 has a backrest segment 311 and an engaging segment 312 that is disposed under and forms a predetermined angle relative to the backrest segment 311. The engaging frame 32 includes an engaging wall 321 that is connected fixedly to the engaging segment 312 of the backrest plate 31, and two pivot mounting walls 322 that extend perpendicularly and respectively from opposite lateral ends of the engaging wall 321 and that are connected pivotally and respectively to the backrest assembly mounting walls 214 of the leg unit 21.

In this embodiment, the support assembly 4 includes two telescopic rods 41 that are spaced apart from each other, first and second positioning seats 42, 44, and first and second pivot rods 43, 45. The telescopic rods 41 interconnect the engaging frame 32 of the backrest assembly 3 and the leg unit 21 of the seat assembly 2. The first positioning seat 42 is mounted to a bottom surface of the seat plate 22 adjacent to the backrest assembly mounting walls 214, and is spaced apart from the engaging frame 32 of the backrest assembly 3. The first pivot rod 43 is for coupling pivotally the telescopic rods 41 to the first positioning seat 42. The second positioning seat 44 is mounted to the engaging wall 321 of the engaging frame 32. The second pivot rod 45 is for coupling pivotally the telescopic rods 41 to the second positioning seat 45.

In this embodiment, the actuating mechanism includes two actuating members 50, a coupling rod 51, a supporting frame 53, a handling device 54, and a drawing unit 56. Each of the actuating members 50 corresponds in position to a respectively one of the telescopic rods 41. The supporting frame 53 is secured to the telescopic rods 41. Each of the telescopic rods 41 is provided with a trigger member 412 operable to enable length adjustment of a corresponding one of the telescopic rods 41 and a protruding plate 413 disposed adjacent to a respective one of the actuating members 50. In this embodiment, the telescopic rods 41 are pneumatic cylinders, and the trigger members 412 are configured as valves for enabling and disabling the length adjustment of the pneumatic cylinders, i.e., the telescopic rods 41.

Each of the actuating members 50 has a spring-abutting portion 502 corresponding in position to the protruding plate 413 of the respective one of the telescopic rods 41, and a controlling portion 501 corresponding in position to the trigger member 412 of the respective one of the telescopic rods 41. The actuating mechanism 5 further includes two springs 52, each of the springs 52 having opposite ends abutting respectively against the spring-abutting portion 502 of the respective one of the actuating members 50 and the protruding plate 413 of the respective one of the telescopic rods 41.

The coupling rod 51 is connected co-movably to the spring-abutting portions 502 of the actuating members 50. The handling device 54 is mounted to the handle mounting wall 213 of the seat assembly 2 and includes a handle 541. The drawing unit 56 includes a connecting member 563 that is connected to the coupling rod 51, a flexible drawing strip 561 that has an end connected to the connecting member 563 and an opposite end connected to the handling device 54, and a bushing 562 that is sleeved on the drawing strip 561 and mounted to the supporting frame 53 to ensure that the part of the drawing strip 561 which is sleeved in the bushing 562 is only movable in a direction parallel to the telescopic rods 41.

Further referring to FIGS. 6 to 8, to adjust inclination of the backrest plate 31 relative to the seat plate 22, the handle 541 is pulled to drive the connecting member 563 and the coupling rod 51 to move away from the backrest plate 31 through the drawing strip 561. The spring-abutting portions 502 of the actuating members 50 are consequently driven to move toward the protruding plates 413 of the respective telescopic rods 41 by virtue of the coupling rod 51 so as to compress the respective springs 52, and the controlling portion 501 of each actuating member 50 enables the trigger member 412 of the respective telescopic rod 41 from a close position (see FIG. 5) to an open position (see FIG. 8), i.e., a length adjustable state, thereby permitting length adjustment of the telescopic rods 41. The drawing unit 56 is operable for driving the actuating members 50 to enable length adjustment of the telescopic rods 41, thereby adjusting inclination of the backrest assembly 3 relative to the seat assembly 2.

After inclination of the backrest plate 31 relative to the seat plate 21 is adjusted to a desired position, the handle 541 is released and the spring-abutting portion 502 of each actuating member 50 is biased away from the respective protruding plate 413 by a restoring force of the respective spring 52. Consequently, the controlling portions 501 of the actuating members 50 are moved away from the trigger members 412 so as to permit the trigger members 412 to move from the open position to the close position, thereby positioning once again the backrest plate 31 relative to the seat plate 22.

To sum up, the advantages of the present invention are as follows. The chair according to the present invention has a relatively simple configuration compared to the conventional backrest adjusting device that is illustrated in FIGS. 1 and 2. Since the inclination adjustment of the backrest plate 31 relative to the seat plate 22 is accomplished by length adjustment of the pneumatic telescopic rods 41, the inclination of the backrest plate 31 can be fine tuned as desired in a stepless manner. Furthermore, the position where the handling device 54 is mounted to the seat plate 21 is not limited due to the flexible drawing strip 561.

Referring to FIG. 9, a second preferred embodiment of the chair according to the present invention has a structure similar to that of the first embodiment. The main difference between this embodiment and the first embodiment resides in the following. In this embodiment, the coupling rod 51 and the supporting frame 53 as illustrated in the first embodiment are omitted. The drawing unit 56 includes two drawing strips 562. Each of the drawing strips 562 has an end connected to the handling device 54 and an opposite end connected to a respective one of the actuating members 50. The drawing unit 56 includes two of the bushings 562 that are mounted respectively on the protruding plates 413 of the telescopic rods 41 and that are sleeved respectively on the drawing strips 562.

The handling device 54 includes a main body 542, an elongated groove 543 formed in the main body 542, and an L-shaped handle 541 that is connected pivotally to the main body 542 at a corner portion 546 of the handle 541, and that has a grip portion 545 disposed distal from the main body 542 and a connecting portion 544 engaging slidably the elongated groove 543 of the main body 542. The drawing strips 561 are connected co-movably to the connecting portion 544 of the handle 541. When the grip portion 545 of the handle 541 is pulled, the connecting portion 544 of the handle 541 is moved along the groove 543, such that the actuating members 50 are driven to enable length adjustment of the telescopic rods 41 through the drawing strips 561. Therefore, the inclination of the backrest plate 31 relative to the seat plate 22 can be adjusted to a desired position. The second preferred embodiment has the same advantages as those of the first preferred embodiment.

While the present invention has been described in connection with what are considered the most practical and preferred embodiments, it is understood that this invention is not limited to the disclosed embodiments but is intended to cover various arrangements included within the spirit and scope of the broadest interpretation so as to encompass all such modifications and equivalent arrangements. 

1. A chair comprising: a seat assembly including a leg unit and a seat plate that is mounted to said leg unit; a backrest assembly including a backrest plate and an engaging frame that interconnects pivotally said backrest plate and said seat assembly; support assembly including at least one telescopic rod that interconnects said engaging frame of said backrest assembly and said leg unit of said seat assembly; and an actuating mechanism including at least one actuating member that corresponds in position to said at least one telescopic rod, and a drawing unit that is coupled to said actuating member and that is operable for driving said actuating member to actuate length adjustment of said telescopic rod so as to adjust inclination of said backrest assembly relative to said seat assembly.
 2. The chair as claimed in claim 1, wherein: said actuating mechanism further includes a handling device that is mounted to said seat assembly; and said drawing unit includes a drawing strip that has an end co-movable with said actuating member and an opposite end connected to said handling device, such that said handling device is operable to move said actuating member through said drawing strip.
 3. The chair as claimed in claim 2, wherein said telescopic rod is provided with a protruding plate disposed adjacent to said actuating member and a trigger member operable to enable the length adjustment of said telescopic rod, said actuating member having a spring-abutting portion that corresponds in position to said protruding plate and a controlling portion that corresponds in position to said trigger member, said actuating mechanism further including a spring that has opposite ends abutting respectively against said spring-abutting portion of said actuating member and said protruding plate.
 4. The chair as claimed in claim 3, wherein said support assembly further includes: a first positioning seat mounted to a bottom surface of said seat plate and spaced apart from said engaging frame of said backrest assembly; a first pivot rod for coupling pivotally said first positioning seat to said telescopic rod; a second positioning seat mounted to said engaging frame; and a second pivot rod for coupling pivotally said second positioning seat to said telescopic rod.
 5. The chair as claimed in claim 1, wherein: said support assembly includes two of said telescopic rods that are spaced apart from each other; said actuating mechanism further includes two of said actuating members that correspond in position to said telescopic rods, respectively, a coupling rod that is connected co-movably to said actuating members, and a handling device that is mounted to said seat assembly; and said drawing unit includes a connecting member that is coupled to said coupling rod, and a drawing strip that has an end connected to said connecting member and an opposite end connected to said handling device, such that said handling device is operable to move said coupling rod and said actuating members through said drawing strip.
 6. The chair as claimed in claim 5, wherein: said actuating mechanism further includes a supporting frame secured to said telescopic rods; and said drawing unit further includes a bushing sleeved on said drawing strip and mounted to said supporting frame.
 7. The chair as claimed in claim 5, wherein each of said telescopic rods is provided with a trigger member operable to enable the length adjustment of corresponding one of said telescopic rods and a protruding plate disposed adjacent to a respective one of said actuating members, each of said actuating members having a spring-abutting portion that corresponds in position to said protruding plate of the respective one of telescopic rods and a controlling portion that corresponds in position to said trigger member of the respective one of said telescopic rods, said actuating mechanism further including two springs each having opposite ends abutting respectively against said spring-abutting portion of a respective one of said actuating members and said protruding plate of a corresponding one of said telescopic rods.
 8. The chair as claimed in claim 7, wherein said support assembly further includes: a first positioning seat mounted to a bottom surface of said seat plate and spaced apart from said engaging frame of said backrest assembly; a first pivot rod for coupling pivotally said first positioning seat to said telescopic rods; a second positioning seat mounted to said engaging frame; and a second pivot rod for coupling pivotally said second positioning seat to said telescopic rods.
 9. The chair as claimed in claim 1, wherein said support assembly includes two of said telescopic rods that are spaced apart from each other, said actuating mechanism further including two of said actuating members that correspond respectively in position to said telescopic rods, and a handling device that is mounted to said seat assembly, said drawing unit including two drawing strips, each of which has an end connected to said handling device and an opposite end connected to a respective one of said actuating members, such that said handling device is operable to move said actuating members through said drawing strip.
 10. The chair as claimed in claim 9, wherein each of said telescopic rods is provided with a trigger member operable to enable the length adjustment of a respective one of said telescopic rods and a protruding plate disposed adjacent to a respective one of said actuating members, each of said actuating members having a spring-abutting portion that corresponds in position to said protruding plate of the respective one of telescopic rods, and a controlling portion that corresponds in position to said trigger member of the respective one of said telescopic rods, said actuating mechanism further including two springs each having opposite ends abutting respectively against said spring-abutting portion of a respective one of said actuating members and said protruding plate of corresponding one of said telescopic rods.
 11. The chair as claimed in claim 10, wherein said support assembly further includes: a first positioning seat mounted to a bottom surface of said seat plate and spaced apart from said engaging frame of said backrest assembly; a first pivot rod for coupling pivotally said first positioning seat to said telescopic rods; a second positioning seat mounted to said engaging frame; and a second pivot rod for coupling pivotally said second positioning seat to said telescopic rods. 